Typescript will not properly compile in VS2012

Question

For no clear reason, Typescript has suddenly stopped reliably compiling into JS code.

Using VS2012, Typescript for VS ver 0.8.3.1 and Web Essentials ver 2.6 (set to "Compile on Save").

I can create a new Typescript file and make simple changes to it (such as export a simnple var or function). I can save TS file and see the JS translation.

HOWEVER, once I add one or more TS definition files (I'm using AMD) and then edit the TS file, NO FURTHER CHANGES APPEAR IN THE CORRESPONDING JS FILE. Edits to the TS file will no longer update the JS. Typescript no longer checks for errors either.

Only when I close and reopen VS2012 will the proper JS file finally appear.

I've uninstalled/reinstalled Typescript, Web Essentials and VS2012 to no avail.

Does anyone have any suggestions on how I can fix this problem? I'm at a loss.

EDIT

This is an entirely reproducible condition. Today, I formatted my drive and re-installed VS2012 anew. USING 64-bit version of Windows 7. Created a new MVC4 project. Created a new TS file. Added a couple of definition files. Attempted to edit the default getDist() function. Saved. No update to the JS file. Removed the definition files. Saved. JS file is properly updated as expected.

IT'S IMPOSSIBLE TO IMAGINE THAT I'M THE ONLY ONE EXPERIENCING THIS PROBLEM!!

Please help!

RE-EDIT Problem solved. See below.

Answer 1

it happened to me,

i solved this issue by setting the build action of the ts file to TypeScriptCompile

Answer 2

Please see : Preview pane for TypeScript missing and/or not updating in VS2012/13

Also check that there are no compile errors in the TS files - a language update can create an error without you noticing, and the new version of WE simply does not update the preview pane like it used to.